This course covers multiple-zone recirculating HVAC systems often require multiple calculation interactions to design efficient and effective systems that can provide acceptable indoor air quality. ASHRAE has developed an Excel workbook that can be used to perform these calculations. This lesson teaches you about this ASHRAE tool. Credit earned on completion of this program will be reported to RCEP. A certificate of completion will be issued to each participant. As such, it does not include content that may be deemed or construed to be an approval or endorsement by NCEES or RCEP.